Thanks for the help,
Actually it does not work for my special case. This is the details I want to do:
When I openning a notes document and change the content, I want to keep the original document, but create a new document with the new edited version.
This is what I did now: on queryOpen event, I keep the all notes item as string (include richtext item), when postquerysave event, I will create a new document with the string I kept on queryopen event, the new UI will create a new document as well. So it looks like the original document is saved (actually it is created based on original data). It works, but I have problem with the richtext item as if I set the string back to richtext field, then I have problem to open this modified document (basically, I changed the richtext to text field).
Ideally, I should use
Call ProbDesc.CopyItemToDocument(doc1, "ProbDesc")
to reset richtext field data.
Please let me know if you have other way.